This study will involve 145 people aged 50-75 years with symptomatic radiographic knee OA and will consist of two types of treatments: Low-level laser therapy (LLLT) and stretching exercises. The patients will be randomly allocated to five study groups LLLT active+Stretch, LLLT placebo+Stretch, Stretch, LLLT and Control (with n=29 each). Treatment frequency will be three sessions/week for all active groups. LLLT will involve the use of a Galium-Arsenide laser (904nm, 40 milliwatts, 3 Joules/point, 27 Joules/knee) over 24 sessions for the monotherapy group and 9 sessions for the LLLT+Stretch groups. Stretching will consist of seven exercises completed over 24 sessions. The control group will receive a booklet.